hello, i have a zeiss zm 35 biogon f2 that is soft at f2. i need an f 1.4 or 1.5 lens that is sharp wide open, preferably a 50mm lens for portraiture needs. the zeiss sonnaar 1.5 zm has an attractive price when offered in the b and h photo video kit with the zeiss ikon body. so i am seriously considering the zeiss sonnar 50. any user feedback on this 50 appreciated. btw if you own the zeiss 35 f2 and feel that lens is sharp at f2, then you and i have different intepretations of the word. thanks in advance.